Manufacture of shoes



P 1941- K. KILBURN 2,257,343

MANUFACTURE OF SHOES Filed April 15, 1955 2 Sheets- Sheet 1 K mam/mg M I Sept. 30, 1941. K. KILBURN 2,257,343

MANUFACTURE OF SHOE S Filed April 15, 1935 2 Sheets-Sheet 2 I /NVg/VTUQ: Kw 04W upon a single sole blank. outsole split from a single sole blank, or having wearer of the shoe.

Patented Sept. 30, 1941 MANUFACTURE or snons I Karl Kilburn, Boston, Mass, assignor to United Shoe Machinery Flemington, N. J.,

Corporation, Borough of a corporation of New Jersey Application April 15, 1935, Serial No. 16,361

1 Claim.

This invention relates to improvements in shoes and shoe soles and to'improved methods of manufacturing same.

For the purpose of securing flexibility in the :foreparts of shoes it is a common present-day practice to employ in the shoe a skeleton insole having an opening which extends through the central portion of its forepart and'is usually filled with a filler of some sort. Frequently the filler consists of a projecting portion which is formed integrally with the outsole of the shoe. It is customary also to produce an insole having a central forepartopening and an outsole having a central forepart projection complemental to the opening in the insole by a splitting operation performed Such an insole and such complemental shapes as would result from splitting them from a single sole blank, are conveniently spoken of as a complemental insoleoutsole combination. The foreparts of shoes made with such complemental insole-outsole combinations ar said to be substantially more flexible than the foreparts of ordinary shoes in which the ball portions of the insoles are of full thickness.

The use of skeleton insoles in shoes has certain disadvantages, however. For example, the use of a filler for the opening in the insole, whether formed integrally with the outsole or otherwise,

produces an undesirable unfinished surface inside the shoe bottom which is ofteninterrupted by the formation. of a ridge or a crevice between the margin of the filler and the edge of the open- ,ing in the insole. Such a ridge or crevice is unsightly if uncovered by a sock lining or otherwise and is very liable to cause discomfort to the Furthermore, the forepart of such an insole is weakened by the skeletonizing operation to such an extent that it is found necessary to strengthen the insole temporarily by attaching to its forepart a thin piece of relatively stifi reinforcing material to prevent the insole from stretching unduly as a result of the reaction of the lasted upper after. the latter has been secured in overlasted position to the margin of the insole and before the outsole has been attached.

It isan object of the present invention to provide for the desired flexibility in the foreparts of shoes without producing any of the undesirable conditions above referred to.

To the accomplishment of this object, and in accordance with the present invention, it is proposed to. prepare an insole by forming in the i formed preferably, but

the forepart at the inner side of the insole (i.-e.,

at the side which is to facethe foot). Thus, at the inner side of the. insole the forepart recess will be bridged by a thin layer integral with the rest of the sole which will provide a smooth, im-

perforate surface inside of the shoe for engagement with the foot, which will serve to strengthen the insole and prevent it from being stretched out of shape by the reaction of the lasted upper, but which will be so thin that .the recessed insole will be scarcely less flexible than if its central forepart had been entirely removed as in the case ofa skeleton-insole;

As herein disclosed such a recessed insole is not necessarily, by splitting it from asole blank in such a manner as to form also from the blank, by the same splitting operation, an outsole having a central forepart projection complemental to the recess in the insole. l

The invention will beexplained with reference to the accompanyin drawings in which Fig. 1 is anelevationalfview of a portion of a .sole rounding machine illustrating the preferred manner of operating upon a sole blank to define outline of a different contour for the insole into which the blank is to be divided;

1 Fig. 2 is a fragmentary View, partially in crosssection and partially in elevation of the sole blank as it appears after being operated upon by the rounding machine shown in Fig. 1; V

- Fig. 3 is a fragmentary sectional view illustra'ting-the operation upon the sole blank of a matrix roll splitting machine which is employed fordividing the blank into an insole and an outsole having complementalforepartportions; I

Fig. 4 is a vieW, partially in vertical section and partially in elevation, of the matrix rolls illustrating the operation of the rolls upon the forepart portion of the sole blank;

Fig. 5 is a cross-sectional view of the sole blank as it appears after it has been operated upon by the matrix rolls and after the material of the blank has reacted from the deforming pressure exerted thereon by the rolls;

' Figs. 6 and '7 are perspective views, respectively, of the insole and the outsole into which the sole blank is divided by the action of the matrix roll splitting machine;

is divided into an insole and an outsole.

ing the insole shown in Fig. 6 as the shoe ap pears after the upper has been worked over the last and the margins of the upper hav been secured in overlasted position upon the insole;

Fig. 9 is a cross-sectional view taken along the line IX-IX of Fig. 8;

Fig. 10 is a view similar to Fig. 9 but showing the shoe as it appears after a filler piece has been applied to the forepart of the shoe bottom and the outsole has been attached;

Fig. 11 is a view, partially in cross-section and partially in perspective, of the forepart of the finished shoe; and

Fig. 12 is a fragmentary cross-sectional. view of a shoe embodying a modification of the construction shown in Fig, 11. r

In the practice of my improved method as herein illustrated a sole blank [6, which is to be divided into an insole and an outsole by a subsequent splitting operation, is first subjected to a rounding operation for determining the marginal contours of the insole and the outsole. It is to be understood, however, that the desired marginal insole and outsole contours may be secured otherwise than by a rounding operation, for example, by the use of a suitabledie or dies and that, if desired, the splitting operation may be performed first and the resulting insole and outsole blanks thereafter cut to the desired marginal contours. Inasmuch as it is usually desirable to have the marginal contour of the insole differ more or less from that of the outsole which is to be assembled therewith, it is preferred, when rounding a sole blank prior to splitting it, to perform the rounding operation by means of a so-called double knife rounding machine such,

for example, as that disclosed in United States Letters Patent No. 2,057,665, granted October 20, 1936, on an application of F. E. Bertrand. As indicated in Fig. 1, such a rounding machine comprises upper and lower patterns 18 and 20 between which" the sole blank I6 is clamped, and upper and lower rounding knives 22 and 24 which are caused to travel around the edges of the patterns l8 and 20, respectively. In the use of the machine just described the lower rounding knife following the contour of the pattern 20 will trim the sole blank and thereby determine the outline of the outsole which is to be split therefrom, while the upper knife following the contour of the pattern I8, which is smaller than the pattern 20, will form a vertical incision in the upper surface of the sole blank, cutting along a path located within the path of the lower knife and thus defining an insole contour which is somewhat smaller than that of the outsole contour and which is not necessarily or ordinarily spaced uniformly from the latter. At the completion of this rounding operation the sole blank will appear as shown in Fig. 2 wherein the rounded edge produced by the knife 24 is indicated at 26 and thevertical incision made by the upper knife 22 is indicated at 28.

After being rounded as above described the sole blank 16, as herein illustrated, is submitted to a splitting operation as a result of which the blank In order to produce, as a result of the splitting operation, a recess in the central forward portion of the insole and a complemental projection upon the corresponding portion of the outsole, the splitting operation may adv-antageously be performed by means of a machine of the general type of that described in United States Letters Patent No. 2,053,304, granted September 8, 1936, on an application 759,846, filed December 31, 1934, in the name of William D. Thomas. As indicated in Fig. 3, such a machine comprises a single, straight-edged splitting knife 30, an adjustable upper matrix roll 32, and a lower feed roll 34 which is yieldingly mounted so as to press the work, that is, the sole blank, toward the upper roll 32. The matrix roll 32 has formed therein a cavity 36 shaped in outline to correspond to that of the recess to be formed in the forepart of the insole, and the roll 34 has formed thereon a projection 38 complemental to the recess in the roll 34. While being operated upon by the rolls 32 and 34 the sole blank is deformed, by the cooperative action of the cavity 36 and the projection 38, as illustrated in Fig. 4. As the deformed portion of the sole blank is advanced past the knife (the cutting edge of which is conventionally indicated at 40 in Fig. 4) the blank is split closer to its incised surface in the central forward portion than in other portions of the blank, and after the blank has left the rolls and has had an opportunity to react from the deforming pressure it will appear as shown in Fig. 5 the blank having been divided into an insole M, an outsole 46,and a small waste rand 48 which is separated from the insole and the outsole members by the intersection of the out made by the splitting knife 30 with the incision'28 made by the rounding knife 22, As a. result of the blank having been deformed, as indicated in Fig. 4, while it was being split, the insole 44, has a recess 56 formed in the central portion of its forepart at its outer side, i. e., the side which is to face the outsole, as best shown in Fig. '7, while the outsole 46 has a projection 52 in its central forward portion which is complemental to the recess 50. As shown, the recess extendsonly part way through the insole so that the relatively thick marginal portion 54 extending peripherally of the forepart of the insole merges, at its inner or foot-engaging side, into a thin portion or layer 56 which is integral with the rest of the insole.

Thus, while the insole has been recessed so as to render it more flexible, its inner surface (which is to be directed toward the foot and which will, in the absence of a sock lining, be exposed to view at the inside of the shoe) will be a smooth, finished, surface which is continuous from one edge of the insole to the other.

In making a shoe embodying the insole 44 and the outsole 46 just described, the insole 44 is assembled with an upper 60 on a last 62, the insole being laid with its unrecessed side against the last bottom, as shown in Fig. 9, and being secured in place by tacks in the usual manner. The upper 6|] comprises the usual layers of upper material, such as upper leather, lining, and doubler, although for clearness of illustration it has been considered unnecessary to indicate'the separate layers. The upper materials, after having been worked over the last in the usual manner, are secured in overlasted position upon the insole, as by means of cement, tacks or staples, the former being conventionally indicated at 64 (Figs. 9 and 10) At the bottom of the recess 50 the thin integral layer 56 which connects the marginal portions of the forepart of the insole will prevent the insole from stretching as a result of any'reaction of the tensioned upper. This renders unnecessary the operation of applying a separate piece of material for either temporarily or permanently reinforcing the forepart of the insole, as is customary in the case of skeleton insoles. Also, of course, there is no temporary reinforcement to be subsequently removed.

Before the outsole is applied, a filler piece 68 of suitable material, such as felt, which is not too readily compressible, is laid within the recess 52 in the insole, the filler piece being of a thickness corresponding to that of the upper 60 and of a marginal contour corresponding to that of the recess 50. The filler 66 is pressed smoothly against the bottom and against the sloping side walls of the recess 50 and serves in effect merely to compensate for the thickness of the upper materials so that the recess at the outer side of the filler piece which is left to be filled by the projection 52 upon the outsole will be no deeper than the height of the projection.

The outsole 46 is preferably attached by means of cement by the use of a sole attaching press, the overlasted margin of the upper and marginal portion of the outsole having been first prepared in the usual manner for the reception of the cement which is conventionally illustrated at 68 in Figs. 10 and 11. The shoe then appears as indicated in Fig. 10 wherein it will be noted that the projection 52 of the outsole together with the filler piece 66 entirely fills the shoe bottom cavity formed by the recess 50 in the insole and the space between the overlasted margins of the upper. The presence of the filler piece 66 insures against the formation of any depression or irregularity in the outsole as a result of the sole attaching pressure. In addition, the filler piece 66 prevents rubbing together of the insole and the outsole as a result of relative movement of these parts as the shoe is flexed in walkmg.

The bottom of a shoe constructed as herein described will be particularly flexible in its forepart regardless of its laminated construction because of the thinness of the recessed central forepart portion of the insole and the inherent flexibility as well as the thinness of the filler piece 66. Moreover, the smooth, imperforate surface of the insole will be comfortable to the foot and will present a finished and attractive appearance so that it will be unnecessary to employ a sock lining.

While the recessed insole has been herein described as having been produced by splitting a sole blank in such a manner as to produce also an outsole having formed thereon an integral projection complemental to the recess in the insole, many of the advantages of the invention may be obtained Without the provision of a specially prepared outsole of that sort. For example, as shown in Fig. 12, an outsole 10 may be employed which is of uniform thickness throughout its forepart. In case such an outsole is employed the central forepart cavity in the shoe bottom may be filled before the outsole is applied with felt or other suitable filling material, as indicated at 72, so as to provide a substantially flush bottom surface for the reception of the outsole.

Having described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

A shoe comprising an insole having a relatively thin central forward portion of uniform thickness surrounded by a thicker portion having a beveled inner margin, an outsole having a rela-- tively thick central forward portion surrounded by a beveled margin complementary to said beveled insole margin, an upper having its marginal portion interposed between the outer marginal portions of said soles but terminating outwardly of the beveled portions thereof, and a filler of a thickness corresponding to that of the upper interposed between the relatively thin portion of the insole and. the relatively thick portion of the outsole, said filler having a marginal portion offset from the plane of its body portion and overextending the entire width of the beveled portions of said insole and said outsole.

KARL KILBURN. 

